状态代码：0 Microsoft.Graph.ServiceException：代码：tooManyRetries 消息：发送请求时遇到超过 3 次重试

Question

当我们尝试使用 Graph API 从日历中获取会议时，我们遇到了异常

获取日历事件的代码：

GraphServiceClient service = new GraphServiceClient(
                new DelegateAuthenticationProvider(
                    async (request) =>
                    {
                        request.Headers.Authorization =
                            new AuthenticationHeaderValue("Bearer", accessToken);
                        await Task.FromResult<string>(null);
                    }));


eventResult = await service.Users[connectedAccountEmailID].Calendars[calendarId].CalendarView.Request(options)
                        .Select("id,subject,organizer,start,end,attendees,showas,isallday,seriesmasterid")
                        .Header("Prefer", "IdType=\"ImmutableId\"")
                        .GetAsync();

我们得到的异常是

exeptionType : System.AggregateException

Status Code: 0
Microsoft.Graph.ServiceException: Code: tooManyRetries
Message: More than 3 retries encountered while sending the request.

   at Microsoft.Graph.HttpProvider.<SendRequestAsync>d__19.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.Graph.HttpProvider.<SendAsync>d__18.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.Graph.BaseRequest.<SendRequestAsync>d__38.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.Graph.BaseRequest.<SendAsync>d__34`1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.Graph.CalendarCalendarViewCollectionRequest.<GetAsync>d__4.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Service.Office365CalendarProviderService.<>c__DisplayClass44_0.<<GetCalendarMeetings>b__0>d.MoveNext()

我检查了代码并确认我们没有同时进行任何并行调用，但仍然遇到限制类型的异常。

任何帮助将不胜感激

Answer 1

此错误表明 .NET SDK 的内置重试处理程序已重试失败请求的最大次数（请参阅https://github.com/microsoftgraph/msgraph-sdk-dotnet-core/blob/2466fdca28d807b727497db7dc8c7767d513f62f/src/Microsoft.Graph.Core/Requests/Middleware/RetryHandler.cs#L132-L137）。三倍是默认的最大重试值。

重试只发生在特定的 HTTP 状态代码（429、503 或 504）中，因此出于某种原因，您在应用中遇到了这种情况。您可能会尝试的一件事是尝试使用 Graph Explorer 对同一用户进行相同的 API 调用。查看 AggregateException 上的其余字段以了解“真正的”异常是什么也可能会有所帮助。网络捕获也可能会暴露更多的调试信息。

如果所有这些都不能提供答案，您可能需要联系support。